Earth auger



Sept. 14, 1943. H, s, BROWN 2,329,388

EARTH AUGER Filed May l2, 1941 2 Sheets-Sheet 1 l @I y /9 ll .f q

` J f6 f3 f5 l 291.2% 1 i /4 5 H. S. BROWN sept. 14, 1943.

Filed May 12 1941 2 Sheets-Sheet 2 :N wk

- Patented Sept. 14, 1943 UNITED IsTATlszs PATENT oFFIcE Ammtyggzi 11:. 393,013

(Cl. Z55- 70) 13 Claims.

My Patent No. 1,807,148, of May 2Q, 1931, discloses an earth auger having a helical mold board of about one turn and a ilap valve hinged to the upper part of the mold board with its free edge adapted to rest on the lower part of the mold board near the cutting edge to close the pas--` sage through the helical mold board when the auger is to be withdrawn from a bore or hole with a load oi' earth upon it. This arrangement was satisfactory in the hands of skilled operators who did not overload the auger, but an untrained operator is apt to drill too deep before attempting to pull the auger out of the bore with the accumulated load of earth and thus will get so much earth above the mold board that the auger cannot be pulled because the loose earth above the auger wedges in the bore. In this condition the auger must be dug out or abandoned, for the flap valve will prevent it from being worked out by reversing or turning backward. Increased upward pull on the auger merely jams the earth above it into a rmer mass.

The principal object of this invention is to provide a iiap valve that will effectually close the passage in the auger when it is to be pulled out with a load of earth and will also allow reverse rotation when overloaded. Generally speaking, this is accomplished by making the valve narrow enough to swing from a position generally in extension of the upper portion of the mold board when the auger is being screwed into the ground to a position lying beneath the upper portion of the mold board when the auger has been reversed, and providing a spring for supporting the flap valve in closed position while the auger is being lifted from a bore with a load of earth upon it.

With this construction the untrained operator may drive the auger until he thinks it should be pulled and then, if he iinds it has been driven too deep into the particular material, he can reverse the auger and work it up to a shallower depth from which it can be pulled.

Further objects and advantages of the invention will appear as the description is read in connection with the accompanying drawings, showing a preferred embodiment of the invention, and in which Fig. 1 is a side elevation of the auger, the flap valve being shown in solid lines in the normally closed position it assumes when the auger is being pulled, and in dotted lines in the two extreme positions it takes when the auger is being driven and when it is'being reversed, respectively.

Fig. 2 is a plan view of the auger, the shank being shown in cross section.

Fig. 3 is a section taken on the line 3 3 of Fig. 2, showing the flap valve in plan.

Figs. 4 and 5 are sections taken on the lines 4--4 and 5--5, respectively. oi Fig. 3.

But these specific drawings and the corresponding description are used for the purpose of disclosure only and are not to be construed as imposing unnecessary limitations on the claims.

The shank III of the auger is customarily squared in cross section, as shown in Fig. 2 where it is surrounded by a spacing sleeve 3, and terminates in a centering or pilot screw I I. Mounted on the shank is a hub I2 equipped with a helical mold board I3 of slightly less than one turn. A mold board of not more than about one and a half turns has an advantage in the ease of movement of dirt therethrough, but the present invention may be used with an auger of any number of turns. The lower, leading edge Il is to be provided with a suitable cutting knife I5 which cuts the earth as the auger is rotated clockwise in Fig. 2. One or more clearance cutters I5 extend downwardly from the lower surface of the mold board I3 and project a little beyond its periphery in order to form the wall of the bore and cut away roots and such like.

The flap valve or shutter plate I6 for closing the passageway, generally indicated by I1, through the mold board is shown in solid lines in Fig. 1, vin the closed position that it naturally takes when the auger is idle or is being pulled upwardly in a bore with a load of earth on it. At A in Fig. 1 it is shown in dotted lines in the position it. assumes while the auger is being driven to drill into the earth and at B it is shown in dotted lines in the position it assumes after the auger has been reversed in the bore.

The upper, trailing edge of the mold board I9 is provided with spaced perforated lugs I8 to cooperate with similar lugs 20 formed on the upper edge of the flap valve or shutter plate by rolling its notched edge over, as best shown at 2| in Fig. 5. The two sets of hinge lugs are pivoted together by a hinge pin 22 passed through them. The lugs I8 extend above the top of the mold board, as indicated at 23 in Figs. 4 and 5, and their inner ends are rounded of! at 24. The

'f ,flap valveor shutter plateis given a slight bend or angle 25 (Figs. 4 and 5) by means of which it alines with the upper surface 23 in position A of Fig. l, and it is made to lie flat againstl the underside of the mold board in position B.

the mold boa-rd.

As will be seen from Fig. 4, the valve or shutter may be swung freely between the normally closed position towards position A without putting the spring under any strain and may be swung from the solid line position towards position B by overcoming the resistance of the spring. Hence, with a spring suited to the size of the auger, the valve or shutter will be supported in the closed solid line position with an appropriate load of earth on the auger or will move to the dotted line position B when the auger is reversed under suillcient load.

As a specific illustration for a mold board of 22 in diameter and a. pitch of 41/4" per turn,

ka spring 21 of ff" steel rod having six turns about a 1A," inside diameter is appropriate.

The valve or shutter must be tapered from the outer edge to the inner edge substantially as shown in Fig. 3 to correspond with the pitch of the mold board, and the free edge should have sufilcient clearance with the lower part of the mold board to prevent objectionable binding and yet not suilicient clearance to leave any substantial opening through which a quantity of loose earth could escape.

From the foregoing it is seen that without any interference with the use of the auger by a skilled operator it is made substantially foolproof in the hands of an unskilled operator. If he drills it into the earth so deeply that it cannot be pulled up, he can turn it backwards and unscrew it, the spring 21 enabling the tlap i6 to yield under the reaction of the dirt to the reverse turning movement of the auger. It may be noted that there is a very wide difference between the reaction of the dirt against the face of the plate I6 when the auger is being pulled upwardly and the similar reaction when the auger is being turned rearwardly. This great difference avoids the necessity for extremely delicate balancing of the strength of the spring 21 against the pressure of the dirt on the flap I6 in normal operation. With the specific dimensions given by way of example, the spring strength is appreciably greater than necessary for normal operation and appreciably less than the maximum it could be while still permitting the ilap I6 to open upon reverse turning of the auger.

I claim: 1. In an earth auger, a helical mold board of the upper portion of the mold board to swing from a position generally in extension of 'the mold board to a position lying along beneath the mold board, and yielding means for holding the valve in an intermediate position with a load of earth on the mold board.

3. In an earth auger, a helical mold board of approximately one turn. a flap valve hinged to the upper portion of 'the mold board to swing from a position generally in extension of the mold board to a position lying `along beneath the mold board, and yielding'means for holding the valve closed betweenvthe upper and lower portions of the mold board with a load of earth on the mold board, said yielding means being capable of holding the valve closed during upward pull of the auger and letting the valve yield to open position upon a reverse turning of the auger when the auger is excessively loaded.

4. In an earth auger, a helical mold board of approximately one turn, a flap valve hinged to the upper portion of the mold board to swing from a position generally in extension ot the mold board as the mold board passes into the earth in boring to a position lying along beneath the mold board as the auger is reversed in the earth, and a spring associated with the hinge for holding the valve in an intermediate position with a load of earth on the mold board.

5. In an earth auger, a helical mold board of approximately one turn, a ap valve hinged to the upper portion of the mold board to swing from a position generally in extension of the mold board to a position lying along beneath the mold board. and yielding means for holding the valve closed between the upper and lower portions of the mold board with a load of earth on the mold board, said yielding means being capable of holding the valve closed during upward pull of the auger and letting the valve yield to open position upon a reverse turning oi' the auger when the auger is excessively loaded, said valve being freely movable between the first named position and the intermediate position.

6. In an earth auger, a helical mold board, a flap valve hinged to one portion of the mold board and of a length to swing past the adjacent convolution of the mold board, and yielding means normally holding it extending toward said adjacent convolution to block the ilow of earth downwardly past said valve.

'7. In an earth auger, a helical mold board, a flap valve hinged to the mold board approxi- `mately one turn above the bottom thereof to swing from 4a position generally in extension oi.' the portion of the mold board therebelow, as it passes into the earth, toward a position lying along beneath the mold board, and a spring for supporting the valve in an inclined position extending between the upper and lower portions of the mold board.

8. In an earth auger, a helical mold board. a flap valve hinged to the mold board approximately one turn above the bottom thereof to swing from a position generally in extension in extension of the portion of the mold board therebelow to a position lying along beneath the mold board, and yielding means for holding the valve in an intermediate Position with a load of earth on the mold board.

9. In an earth auger, a helical mold board, a flap valve hinged to the mold board approximately one turn above the bottom thereof to swing from a position generally in extension of the portion of the mold board therebelow to a position lying along beneath the mold board, and yielding means for holding the valve closed between the upper and lower portions of the mold board with a load of earth on the mold board, said yielding means being capable of holding the valve closed during upward pull of the auger and letting the valve yield to open position upon a reverse turning of the auger when the auger is excessively loaded.

10. In an earth auger, a helical mold board, a flap valve hinged to the mold board approximately one turn above the bottom thereof to swing from a position generally in extension of the portion of the mold board therebelow as the mold board passes into the earth in boring to a position lying along beneath the mold board as the auger is reversed in the earth, and a spring associated with the hinge for holding the valve in an intermediate position with a load of earth on the mold board.

11. In an earth auger, a helical mold board, a flap valve hinged to the mold board approximately one turn above the bottom thereof to swing from a position generally in extension of the portion of the mold board therebelow to a position lying along beneath the mold board, and yielding means for holding the valve closed between the upper and lower portions of the mold board with a load of earth on the mold board, said yielding means being capable of holding the valve closed during upward pull of the auger and letting the valve yield to open position upon a reverse turning of the auger when the auger is excessively loaded, said valve being freely movable between the ilrst named position and the intermediate p0sition.

12. In an earth auger, a helical mold board, a ilap valve hinged to the mold board approximately one-tum above the bottom thereof to swing between an intermediate position extending toward the lower portion of the mold board to block the ilow of loose material from the mold board, a drilling position on the side of the intermediate position toward which the mold board extends upwardly, and a reverse turning position on the opposite side of the intermediate position, the ilap valve in its drilling position and in its reverse turning position permitting loose material to flow onto and from the mold board respectively, and means eiective during lifting of the earth auger for preventing the flap valve from swinging from the intermediate position to the reverse turning position.

13. In an earth auger, a helical mold board, a ilap valve hinged to the mold board approximately one turn above the bottom thereof to Iswing between an intermediate position extending toward the lower portion of the mold board to block the ilow of loose material from the mold board, a drilling position on the side of the intermediate position toward which the mold board extends upwardly, and a reverse turning position on the opposite side of the intermediate position, the flap valve in its drilling positionand in its reverse turning position permitting loose material to flow onto and from the mold board respectively, and means effective during lifting of the earth auger for preventing the flap valve from swinging from the intermediate position to the reverse turning position. said valve being freely movable between the intermediate position and the drilling position.

HUGH S. BROWN. 

